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/*
 * Copyright (c) 2012, Stephen Colebourne & Michael Nascimento Santos
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *  * Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 *  * Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 *  * Neither the name of JSR-310 nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package java.time.chrono;

import static java.time.temporal.ChronoField.ALIGNED_DAY_OF_WEEK_IN_MONTH;
import static java.time.temporal.ChronoField.ALIGNED_DAY_OF_WEEK_IN_YEAR;
import static java.time.temporal.ChronoField.ALIGNED_WEEK_OF_MONTH;
import static java.time.temporal.ChronoField.ALIGNED_WEEK_OF_YEAR;
import static java.time.temporal.ChronoField.DAY_OF_MONTH;
import static java.time.temporal.ChronoField.MONTH_OF_YEAR;
import static java.time.temporal.ChronoField.YEAR;

import java.io.IOException;
import java.io.InvalidObjectException;
import java.io.ObjectInput;
import java.io.ObjectInputStream;
import java.io.ObjectOutput;
import java.io.Serializable;
import java.time.Clock;
import java.time.DateTimeException;
import java.time.LocalDate;
import java.time.LocalTime;
import java.time.ZoneId;
import java.time.temporal.ChronoField;
import java.time.temporal.TemporalAccessor;
import java.time.temporal.TemporalAdjuster;
import java.time.temporal.TemporalAmount;
import java.time.temporal.TemporalField;
import java.time.temporal.TemporalQuery;
import java.time.temporal.TemporalUnit;
import java.time.temporal.UnsupportedTemporalTypeException;
import java.time.temporal.ValueRange;

/**
 * A date in the Hijrah calendar system.
 * <p>
 * This date operates using one of several variants of the
 * {@linkplain HijrahChronology Hijrah calendar}.
 * <p>
 * The Hijrah calendar has a different total of days in a year than
 * Gregorian calendar, and the length of each month is based on the period
 * of a complete revolution of the moon around the earth
 * (as between successive new moons).
 * Refer to the {@link HijrahChronology} for details of supported variants.
 * <p>
 * Each HijrahDate is created bound to a particular HijrahChronology,
 * The same chronology is propagated to each HijrahDate computed from the date.
 * To use a different Hijrah variant, its HijrahChronology can be used
 * to create new HijrahDate instances.
 * Alternatively, the {@link #withVariant} method can be used to convert
 * to a new HijrahChronology.
 *
 * <p>
 * This is a <a href="{@docRoot}/java/lang/doc-files/ValueBased.html">value-based</a>
 * class; use of identity-sensitive operations (including reference equality
 * ({@code ==}), identity hash code, or synchronization) on instances of
 * {@code HijrahDate} may have unpredictable results and should be avoided.
 * The {@code equals} method should be used for comparisons.
 *
 * @implSpec This class is immutable and thread-safe.
 * @since 1.8
 */
public final class HijrahDate
    extends ChronoLocalDateImpl<HijrahDate>
    implements ChronoLocalDate, Serializable {

  /**
   * Serialization version.
   */
  private static final long serialVersionUID = -5207853542612002020L;
  /**
   * The Chronology of this HijrahDate.
   */
  private final transient HijrahChronology chrono;
  /**
   * The proleptic year.
   */
  private final transient int prolepticYear;
  /**
   * The month-of-year.
   */
  private final transient int monthOfYear;
  /**
   * The day-of-month.
   */
  private final transient int dayOfMonth;

  //-------------------------------------------------------------------------

  /**
   * Obtains an instance of {@code HijrahDate} from the Hijrah proleptic year,
   * month-of-year and day-of-month.
   *
   * @param prolepticYear the proleptic year to represent in the Hijrah calendar
   * @param monthOfYear the month-of-year to represent, from 1 to 12
   * @param dayOfMonth the day-of-month to represent, from 1 to 30
   * @return the Hijrah date, never null
   * @throws DateTimeException if the value of any field is out of range
   */
  static HijrahDate of(HijrahChronology chrono, int prolepticYear, int monthOfYear,
      int dayOfMonth) {
    return new HijrahDate(chrono, prolepticYear, monthOfYear, dayOfMonth);
  }

  /**
   * Returns a HijrahDate for the chronology and epochDay.
   *
   * @param chrono The Hijrah chronology
   * @param epochDay the epoch day
   * @return a HijrahDate for the epoch day; non-null
   */
  static HijrahDate ofEpochDay(HijrahChronology chrono, long epochDay) {
    return new HijrahDate(chrono, epochDay);
  }

  //-----------------------------------------------------------------------

  /**
   * Obtains the current {@code HijrahDate} of the Islamic Umm Al-Qura calendar
   * in the default time-zone.
   * <p>
   * This will query the {@link Clock#systemDefaultZone() system clock} in the default
   * time-zone to obtain the current date.
   * <p>
   * Using this method will prevent the ability to use an alternate clock for testing
   * because the clock is hard-coded.
   *
   * @return the current date using the system clock and default time-zone, not null
   */
  public static HijrahDate now() {
    return now(Clock.systemDefaultZone());
  }

  /**
   * Obtains the current {@code HijrahDate} of the Islamic Umm Al-Qura calendar
   * in the specified time-zone.
   * <p>
   * This will query the {@link Clock#system(ZoneId) system clock} to obtain the current date.
   * Specifying the time-zone avoids dependence on the default time-zone.
   * <p>
   * Using this method will prevent the ability to use an alternate clock for testing
   * because the clock is hard-coded.
   *
   * @param zone the zone ID to use, not null
   * @return the current date using the system clock, not null
   */
  public static HijrahDate now(ZoneId zone) {
    return now(Clock.system(zone));
  }

  /**
   * Obtains the current {@code HijrahDate} of the Islamic Umm Al-Qura calendar
   * from the specified clock.
   * <p>
   * This will query the specified clock to obtain the current date - today.
   * Using this method allows the use of an alternate clock for testing.
   * The alternate clock may be introduced using {@linkplain Clock dependency injection}.
   *
   * @param clock the clock to use, not null
   * @return the current date, not null
   * @throws DateTimeException if the current date cannot be obtained
   */
  public static HijrahDate now(Clock clock) {
    return HijrahDate.ofEpochDay(HijrahChronology.INSTANCE, LocalDate.now(clock).toEpochDay());
  }

  /**
   * Obtains a {@code HijrahDate} of the Islamic Umm Al-Qura calendar
   * from the proleptic-year, month-of-year and day-of-month fields.
   * <p>
   * This returns a {@code HijrahDate} with the specified fields.
   * The day must be valid for the year and month, otherwise an exception will be thrown.
   *
   * @param prolepticYear the Hijrah proleptic-year
   * @param month the Hijrah month-of-year, from 1 to 12
   * @param dayOfMonth the Hijrah day-of-month, from 1 to 30
   * @return the date in Hijrah calendar system, not null
   * @throws DateTimeException if the value of any field is out of range, or if the day-of-month is
   * invalid for the month-year
   */
  public static HijrahDate of(int prolepticYear, int month, int dayOfMonth) {
    return HijrahChronology.INSTANCE.date(prolepticYear, month, dayOfMonth);
  }

  /**
   * Obtains a {@code HijrahDate} of the Islamic Umm Al-Qura calendar from a temporal object.
   * <p>
   * This obtains a date in the Hijrah calendar system based on the specified temporal.
   * A {@code TemporalAccessor} represents an arbitrary set of date and time information,
   * which this factory converts to an instance of {@code HijrahDate}.
   * <p>
   * The conversion typically uses the {@link ChronoField#EPOCH_DAY EPOCH_DAY}
   * field, which is standardized across calendar systems.
   * <p>
   * This method matches the signature of the functional interface {@link TemporalQuery}
   * allowing it to be used as a query via method reference, {@code HijrahDate::from}.
   *
   * @param temporal the temporal object to convert, not null
   * @return the date in Hijrah calendar system, not null
   * @throws DateTimeException if unable to convert to a {@code HijrahDate}
   */
  public static HijrahDate from(TemporalAccessor temporal) {
    return HijrahChronology.INSTANCE.date(temporal);
  }

  //-----------------------------------------------------------------------

  /**
   * Constructs an {@code HijrahDate} with the proleptic-year, month-of-year and
   * day-of-month fields.
   *
   * @param chrono The chronology to create the date with
   * @param prolepticYear the proleptic year
   * @param monthOfYear the month of year
   * @param dayOfMonth the day of month
   */
  private HijrahDate(HijrahChronology chrono, int prolepticYear, int monthOfYear, int dayOfMonth) {
    // Computing the Gregorian day checks the valid ranges
    chrono.getEpochDay(prolepticYear, monthOfYear, dayOfMonth);

    this.chrono = chrono;
    this.prolepticYear = prolepticYear;
    this.monthOfYear = monthOfYear;
    this.dayOfMonth = dayOfMonth;
  }

  /**
   * Constructs an instance with the Epoch Day.
   *
   * @param epochDay the epochDay
   */
  private HijrahDate(HijrahChronology chrono, long epochDay) {
    int[] dateInfo = chrono.getHijrahDateInfo((int) epochDay);

    this.chrono = chrono;
    this.prolepticYear = dateInfo[0];
    this.monthOfYear = dateInfo[1];
    this.dayOfMonth = dateInfo[2];
  }

  //-----------------------------------------------------------------------

  /**
   * Gets the chronology of this date, which is the Hijrah calendar system.
   * <p>
   * The {@code Chronology} represents the calendar system in use.
   * The era and other fields in {@link ChronoField} are defined by the chronology.
   *
   * @return the Hijrah chronology, not null
   */
  @Override
  public HijrahChronology getChronology() {
    return chrono;
  }

  /**
   * Gets the era applicable at this date.
   * <p>
   * The Hijrah calendar system has one era, 'AH',
   * defined by {@link HijrahEra}.
   *
   * @return the era applicable at this date, not null
   */
  @Override
  public HijrahEra getEra() {
    return HijrahEra.AH;
  }

  /**
   * Returns the length of the month represented by this date.
   * <p>
   * This returns the length of the month in days.
   * Month lengths in the Hijrah calendar system vary between 29 and 30 days.
   *
   * @return the length of the month in days
   */
  @Override
  public int lengthOfMonth() {
    return chrono.getMonthLength(prolepticYear, monthOfYear);
  }

  /**
   * Returns the length of the year represented by this date.
   * <p>
   * This returns the length of the year in days.
   * A Hijrah calendar system year is typically shorter than
   * that of the ISO calendar system.
   *
   * @return the length of the year in days
   */
  @Override
  public int lengthOfYear() {
    return chrono.getYearLength(prolepticYear);
  }

  //-----------------------------------------------------------------------
  @Override
  public ValueRange range(TemporalField field) {
    if (field instanceof ChronoField) {
      if (isSupported(field)) {
        ChronoField f = (ChronoField) field;
        switch (f) {
          case DAY_OF_MONTH:
            return ValueRange.of(1, lengthOfMonth());
          case DAY_OF_YEAR:
            return ValueRange.of(1, lengthOfYear());
          case ALIGNED_WEEK_OF_MONTH:
            return ValueRange.of(1, 5);  // TODO
          // TODO does the limited range of valid years cause years to
          // start/end part way through? that would affect range
        }
        return getChronology().range(f);
      }
      throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
    }
    return field.rangeRefinedBy(this);
  }

  @Override
  public long getLong(TemporalField field) {
    if (field instanceof ChronoField) {
      switch ((ChronoField) field) {
        case DAY_OF_WEEK:
          return getDayOfWeek();
        case ALIGNED_DAY_OF_WEEK_IN_MONTH:
          return ((getDayOfWeek() - 1) % 7) + 1;
        case ALIGNED_DAY_OF_WEEK_IN_YEAR:
          return ((getDayOfYear() - 1) % 7) + 1;
        case DAY_OF_MONTH:
          return this.dayOfMonth;
        case DAY_OF_YEAR:
          return this.getDayOfYear();
        case EPOCH_DAY:
          return toEpochDay();
        case ALIGNED_WEEK_OF_MONTH:
          return ((dayOfMonth - 1) / 7) + 1;
        case ALIGNED_WEEK_OF_YEAR:
          return ((getDayOfYear() - 1) / 7) + 1;
        case MONTH_OF_YEAR:
          return monthOfYear;
        case PROLEPTIC_MONTH:
          return getProlepticMonth();
        case YEAR_OF_ERA:
          return prolepticYear;
        case YEAR:
          return prolepticYear;
        case ERA:
          return getEraValue();
      }
      throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
    }
    return field.getFrom(this);
  }

  private long getProlepticMonth() {
    return prolepticYear * 12L + monthOfYear - 1;
  }

  @Override
  public HijrahDate with(TemporalField field, long newValue) {
    if (field instanceof ChronoField) {
      ChronoField f = (ChronoField) field;
      // not using checkValidIntValue so EPOCH_DAY and PROLEPTIC_MONTH work
      chrono.range(f).checkValidValue(newValue, f);    // TODO: validate value
      int nvalue = (int) newValue;
      switch (f) {
        case DAY_OF_WEEK:
          return plusDays(newValue - getDayOfWeek());
        case ALIGNED_DAY_OF_WEEK_IN_MONTH:
          return plusDays(newValue - getLong(ALIGNED_DAY_OF_WEEK_IN_MONTH));
        case ALIGNED_DAY_OF_WEEK_IN_YEAR:
          return plusDays(newValue - getLong(ALIGNED_DAY_OF_WEEK_IN_YEAR));
        case DAY_OF_MONTH:
          return resolvePreviousValid(prolepticYear, monthOfYear, nvalue);
        case DAY_OF_YEAR:
          return plusDays(Math.min(nvalue, lengthOfYear()) - getDayOfYear());
        case EPOCH_DAY:
          return new HijrahDate(chrono, newValue);
        case ALIGNED_WEEK_OF_MONTH:
          return plusDays((newValue - getLong(ALIGNED_WEEK_OF_MONTH)) * 7);
        case ALIGNED_WEEK_OF_YEAR:
          return plusDays((newValue - getLong(ALIGNED_WEEK_OF_YEAR)) * 7);
        case MONTH_OF_YEAR:
          return resolvePreviousValid(prolepticYear, nvalue, dayOfMonth);
        case PROLEPTIC_MONTH:
          return plusMonths(newValue - getProlepticMonth());
        case YEAR_OF_ERA:
          return resolvePreviousValid(prolepticYear >= 1 ? nvalue : 1 - nvalue, monthOfYear,
              dayOfMonth);
        case YEAR:
          return resolvePreviousValid(nvalue, monthOfYear, dayOfMonth);
        case ERA:
          return resolvePreviousValid(1 - prolepticYear, monthOfYear, dayOfMonth);
      }
      throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
    }
    return super.with(field, newValue);
  }

  private HijrahDate resolvePreviousValid(int prolepticYear, int month, int day) {
    int monthDays = chrono.getMonthLength(prolepticYear, month);
    if (day > monthDays) {
      day = monthDays;
    }
    return HijrahDate.of(chrono, prolepticYear, month, day);
  }

  /**
   * {@inheritDoc}
   *
   * @throws DateTimeException if unable to make the adjustment. For example, if the adjuster
   * requires an ISO chronology
   * @throws ArithmeticException {@inheritDoc}
   */
  @Override
  public HijrahDate with(TemporalAdjuster adjuster) {
    return super.with(adjuster);
  }

  /**
   * Returns a {@code HijrahDate} with the Chronology requested.
   * <p>
   * The year, month, and day are checked against the new requested
   * HijrahChronology.  If the chronology has a shorter month length
   * for the month, the day is reduced to be the last day of the month.
   *
   * @param chronology the new HijrahChonology, non-null
   * @return a HijrahDate with the requested HijrahChronology, non-null
   */
  public HijrahDate withVariant(HijrahChronology chronology) {
    if (chrono == chronology) {
      return this;
    }
    // Like resolvePreviousValid the day is constrained to stay in the same month
    int monthDays = chronology.getDayOfYear(prolepticYear, monthOfYear);
    return HijrahDate.of(chronology, prolepticYear, monthOfYear,
        (dayOfMonth > monthDays) ? monthDays : dayOfMonth);
  }

  /**
   * {@inheritDoc}
   *
   * @throws DateTimeException {@inheritDoc}
   * @throws ArithmeticException {@inheritDoc}
   */
  @Override
  public HijrahDate plus(TemporalAmount amount) {
    return super.plus(amount);
  }

  /**
   * {@inheritDoc}
   *
   * @throws DateTimeException {@inheritDoc}
   * @throws ArithmeticException {@inheritDoc}
   */
  @Override
  public HijrahDate minus(TemporalAmount amount) {
    return super.minus(amount);
  }

  @Override
  public long toEpochDay() {
    return chrono.getEpochDay(prolepticYear, monthOfYear, dayOfMonth);
  }

  /**
   * Gets the day-of-year field.
   * <p>
   * This method returns the primitive {@code int} value for the day-of-year.
   *
   * @return the day-of-year
   */
  private int getDayOfYear() {
    return chrono.getDayOfYear(prolepticYear, monthOfYear) + dayOfMonth;
  }

  /**
   * Gets the day-of-week value.
   *
   * @return the day-of-week; computed from the epochday
   */
  private int getDayOfWeek() {
    int dow0 = (int) Math.floorMod(toEpochDay() + 3, 7);
    return dow0 + 1;
  }

  /**
   * Gets the Era of this date.
   *
   * @return the Era of this date; computed from epochDay
   */
  private int getEraValue() {
    return (prolepticYear > 1 ? 1 : 0);
  }

  //-----------------------------------------------------------------------

  /**
   * Checks if the year is a leap year, according to the Hijrah calendar system rules.
   *
   * @return true if this date is in a leap year
   */
  @Override
  public boolean isLeapYear() {
    return chrono.isLeapYear(prolepticYear);
  }

  //-----------------------------------------------------------------------
  @Override
  HijrahDate plusYears(long years) {
    if (years == 0) {
      return this;
    }
    int newYear = Math.addExact(this.prolepticYear, (int) years);
    return resolvePreviousValid(newYear, monthOfYear, dayOfMonth);
  }

  @Override
  HijrahDate plusMonths(long monthsToAdd) {
    if (monthsToAdd == 0) {
      return this;
    }
    long monthCount = prolepticYear * 12L + (monthOfYear - 1);
    long calcMonths = monthCount + monthsToAdd;  // safe overflow
    int newYear = chrono.checkValidYear(Math.floorDiv(calcMonths, 12L));
    int newMonth = (int) Math.floorMod(calcMonths, 12L) + 1;
    return resolvePreviousValid(newYear, newMonth, dayOfMonth);
  }

  @Override
  HijrahDate plusWeeks(long weeksToAdd) {
    return super.plusWeeks(weeksToAdd);
  }

  @Override
  HijrahDate plusDays(long days) {
    return new HijrahDate(chrono, toEpochDay() + days);
  }

  @Override
  public HijrahDate plus(long amountToAdd, TemporalUnit unit) {
    return super.plus(amountToAdd, unit);
  }

  @Override
  public HijrahDate minus(long amountToSubtract, TemporalUnit unit) {
    return super.minus(amountToSubtract, unit);
  }

  @Override
  HijrahDate minusYears(long yearsToSubtract) {
    return super.minusYears(yearsToSubtract);
  }

  @Override
  HijrahDate minusMonths(long monthsToSubtract) {
    return super.minusMonths(monthsToSubtract);
  }

  @Override
  HijrahDate minusWeeks(long weeksToSubtract) {
    return super.minusWeeks(weeksToSubtract);
  }

  @Override
  HijrahDate minusDays(long daysToSubtract) {
    return super.minusDays(daysToSubtract);
  }

  @Override        // for javadoc and covariant return type
  @SuppressWarnings("unchecked")
  public final ChronoLocalDateTime<HijrahDate> atTime(LocalTime localTime) {
    return (ChronoLocalDateTime<HijrahDate>) super.atTime(localTime);
  }

  @Override
  public ChronoPeriod until(ChronoLocalDate endDate) {
    // TODO: untested
    HijrahDate end = getChronology().date(endDate);
    long totalMonths = (end.prolepticYear - this.prolepticYear) * 12 + (end.monthOfYear
        - this.monthOfYear);  // safe
    int days = end.dayOfMonth - this.dayOfMonth;
    if (totalMonths > 0 && days < 0) {
      totalMonths--;
      HijrahDate calcDate = this.plusMonths(totalMonths);
      days = (int) (end.toEpochDay() - calcDate.toEpochDay());  // safe
    } else if (totalMonths < 0 && days > 0) {
      totalMonths++;
      days -= end.lengthOfMonth();
    }
    long years = totalMonths / 12;  // safe
    int months = (int) (totalMonths % 12);  // safe
    return getChronology().period(Math.toIntExact(years), months, days);
  }

  //-------------------------------------------------------------------------

  /**
   * Compares this date to another date, including the chronology.
   * <p>
   * Compares this {@code HijrahDate} with another ensuring that the date is the same.
   * <p>
   * Only objects of type {@code HijrahDate} are compared, other types return false.
   * To compare the dates of two {@code TemporalAccessor} instances, including dates
   * in two different chronologies, use {@link ChronoField#EPOCH_DAY} as a comparator.
   *
   * @param obj the object to check, null returns false
   * @return true if this is equal to the other date and the Chronologies are equal
   */
  @Override  // override for performance
  public boolean equals(Object obj) {
    if (this == obj) {
      return true;
    }
    if (obj instanceof HijrahDate) {
      HijrahDate otherDate = (HijrahDate) obj;
      return prolepticYear == otherDate.prolepticYear
          && this.monthOfYear == otherDate.monthOfYear
          && this.dayOfMonth == otherDate.dayOfMonth
          && getChronology().equals(otherDate.getChronology());
    }
    return false;
  }

  /**
   * A hash code for this date.
   *
   * @return a suitable hash code based only on the Chronology and the date
   */
  @Override  // override for performance
  public int hashCode() {
    int yearValue = prolepticYear;
    int monthValue = monthOfYear;
    int dayValue = dayOfMonth;
    return getChronology().getId().hashCode() ^ (yearValue & 0xFFFFF800)
        ^ ((yearValue << 11) + (monthValue << 6) + (dayValue));
  }

  //-----------------------------------------------------------------------

  /**
   * Defend against malicious streams.
   *
   * @param s the stream to read
   * @throws InvalidObjectException always
   */
  private void readObject(ObjectInputStream s) throws InvalidObjectException {
    throw new InvalidObjectException("Deserialization via serialization delegate");
  }

  /**
   * Writes the object using a
   * <a href="../../../serialized-form.html#java.time.chrono.Ser">dedicated serialized form</a>.
   *
   * @return the instance of {@code Ser}, not null
   * @serialData <pre>
   *  out.writeByte(6);                 // identifies a HijrahDate
   *  out.writeObject(chrono);          // the HijrahChronology variant
   *  out.writeInt(get(YEAR));
   *  out.writeByte(get(MONTH_OF_YEAR));
   *  out.writeByte(get(DAY_OF_MONTH));
   * </pre>
   */
  private Object writeReplace() {
    return new Ser(Ser.HIJRAH_DATE_TYPE, this);
  }

  void writeExternal(ObjectOutput out) throws IOException {
    // HijrahChronology is implicit in the Hijrah_DATE_TYPE
    out.writeObject(getChronology());
    out.writeInt(get(YEAR));
    out.writeByte(get(MONTH_OF_YEAR));
    out.writeByte(get(DAY_OF_MONTH));
  }

  static HijrahDate readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
    HijrahChronology chrono = (HijrahChronology) in.readObject();
    int year = in.readInt();
    int month = in.readByte();
    int dayOfMonth = in.readByte();
    return chrono.date(year, month, dayOfMonth);
  }

}
